Hierarchical hybrids of carbon nanotubes in amphiphilic poly(ethylene oxide)-block-polyaniline through a facile method: from smooth to thorny

A facile approach was developed to synthesize conjugated block copolymer (BCP) poly(ethylene oxide)-b-polyaniline (PEO-PANI). Aldehyde group-terminated PEO was prepared by an esterification reaction of p-formylbenzoic acid and PEO and then reacted with PANI from chemical oxidative polymerization. FT-IR, (1)H NMR, and GPC results indicated that BCPs with different PEO block lengths were successfully synthesized. Moreover, the BCPs were employed to noncovalently modify multiwalled carbon nanotubes (MWNTs) through either the direct or indirect method. In the former method, transmission electron microscopy images showed that a core-shell MWNT@BCP hybrid with a shell thickness of gyration diameter of PEO block (2Rg,PEO) was obtained in 1-methyl-2-pyrrolidone (NMP). These hybrids can be well dispersed in many common solvents and poly(vinyl alcohol) matrix. With the increase of PEO block length, the stability of the MWNT dispersion would be highly improved. Interestingly, in the indirect method where deionized water was added to the NMP solution of BCP/MWNT mixture, the surface of the hybrid micelles encapsulated with MWNTs changed from smooth into hierarchically thorny with the increase of BCP/MWNT weight ratio. In this case, the water contact angle had a minimum value of ~70° at the ratio of 1/8, indicating that the hierarchical thorns followed a Cassie-Baxter regime rather than a Wenzel one. A possible formation mechanism of the unique structure was also proposed.

Preparation and application of anti-HBx/anti-CD3 bispecific monoclonal antibody (BsAb) retargeting effector cells for lysis of human hepatoma xenografts in nude mice

Evidence indicated that the x gene of human HBV can cause cancer in transgenic mice, moreover, HBxAg was so far the most frequent and strong antigen among those HBV markers expressed in hepatocellular carcinoma (HCC) tissues. Aiming to enhance killing of HCC by effector cells, we established an anti-HBx/anti-CD3 hybrid-hybridomas by fusion of anti-HBx hybridoma cells with FITC-labeled anti-CD3 HAT sensitive cells, and followed by FACStar sterile cell sorting, HAT selection and eventually verified by ELISA and double bridging assay. Using two color cytometric analysis, we found that bispecific monoclonal antibody (BsAb) remarkably enhanced in vitro effector-target cell conjugates (48.3% vs. 8.5%). In in vivo study, BsAb retargeting effector cells were significantly more effective than that of effector cells alone in shrinkage of LTNM4 HCC xenografts (HBxAg positive) in nude mice, not only in fresh inoculated tumors but also in established tumors (p<0.01, p<0.01, respectively). Besides, pronounced apoptotic cell death and infiltration of lymphocytes in the peripheral of tumor nodules can also be witnessed in the tissues treated by BsAb plus effector cells, but not in the controls. The results demonstrated that antiHBx/anti-CD3 BsAb was able to redirect effector cells for lysis of HBxAg positive HCC cells both in vitro and in vivo and it also indicated that shrinkage of tumors in nude mice with therapy of BsAb retargeting effector cells was partially due to initiation of apoptotic cell death.

The antitumor natural compound falcarindiol promotes cancer cell death by inducing endoplasmic reticulum stress

Falcarindiol (FAD) is a natural polyyne with various beneficial biological activities. We show here that FAD preferentially kills colon cancer cells but not normal colon epithelial cells. Furthermore, FAD inhibits tumor growth in a xenograft tumor model and exhibits strong synergistic killing of cancer cells with 5-fluorouracil, an approved cancer chemotherapeutic drug. We demonstrate that FAD-induced cell death is mediated by induction of endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR). Decreasing the level of ER stress, either by overexpressing the ER chaperone protein glucose-regulated protein 78 (GRP78) or by knockout of components of the UPR pathway, reduces FAD-induced apoptosis. In contrast, increasing the level of ER stress by knocking down GRP78 potentiates FAD-induced apoptosis. Finally, FAD-induced ER stress and apoptosis is correlated with the accumulation of ubiquitinated proteins, suggesting that FAD functions at least in part by interfering with proteasome function, leading to the accumulation of unfolded protein and induction of ER stress. Consistent with this, inhibition of protein synthesis by cycloheximide significantly decreases the accumulation of ubiquitinated proteins and blocks FAD-induced ER stress and cell death. Taken together, our study shows that FAD is a potential new anticancer agent that exerts its activity through inducing ER stress and apoptosis.

New insights into hard phases of CoCrMo metal-on-metal hip replacements

The microstructural and mechanical properties of the hard phases in CoCrMo prosthetic alloys in both cast and wrought conditions were examined using transmission electron microscopy and nanoindentation. Besides the known carbides of M(23)C(6)-type (M=Cr, Mo, Co) and M(6)C-type which are formed by either eutectic solidification or precipitation, a new mixed-phase hard constituent has been found in the cast alloys, which is composed of ∼100 nm fine grains. The nanosized grains were identified to be mostly of M(23)C(6) type using nano-beam precession electron diffraction, and the chemical composition varied from grain to grain being either Cr- or Co-rich. In contrast, the carbides within the wrought alloy having the same M(23)C(6) structure were homogeneous, which can be attributed to the repeated heating and deformation steps. Nanoindentation measurements showed that the hardness of the hard phase mixture in the cast specimen was ∼15.7 GPa, while the M(23)C(6) carbides in the wrought alloy were twice as hard (∼30.7 GPa). The origin of the nanostructured hard phase mixture was found to be related to slow cooling during casting. Mixed hard phases were produced at a cooling rate of 0.2 °C/s, whereas single phase carbides were formed at a cooling rate of 50 °C/s. This is consistent with sluggish kinetics and rationalizes different and partly conflicting microstructural results in the literature, and could be a source of variations in the performance of prosthetic devices in-vivo.

SU-E-T-426: Comparison of HDR Brachytherapy for Cervix Cancer Using an Adaptive Simulated Annealing Program and Oncentra- for Simultaneously Integrated Boost

PURPOSE

High dose rate (HDR) volumetric brachytherapy is an effective method of treating advanced cervix carcinoma. Local failure is associated with multiple factors including higher maximal standardized uptake value (SUV) values in fluorodeoxyglucose positron emission tomography (FDG- PET) scans. The purpose of this study is to evaluate the ability to simultaneously boost regions of high SUV values using an in-house adaptive simulated annealing (ASA) algorithm and the Oncentra® (Nucletron V.B., Veenendaal, The Netherlands) treatment planning system, thereby potentially improving local control.

METHODS

Five cervix cancers were evaluated for brachytherapy treatment (tandem/ring and/or interstitial needles). MRI and PET images were obtained post-implant and fused with treatment planning CTs to define a high-risk (HR) CTV (cervix and tumor on MRI) and GTV (volume with >50% of the maximum SUV on PET). The prescribed dose was 5-6 Gy to the HR CTV and 7-9 Gy to the GTV. Treatment plans were first generated in Oncentra® with IPSA followed by manual graphic optimization by the physician. Plans were also independently optimized using the ASA program. The two plans were compared side by side and one was chosen for treatment. Dose-volume parameters including D90, V100 of targets, D2cc to the critical organs, and generalized equivalent uniform dose (gEUD) of all structures were compared between the ASA and the Oncentra plans.

RESULTS

Both ASA and Oncentra plans were considered acceptable by the physician in four of five cases. Two ASA plans were chosen due to better critical organ sparing and tumor coverage. Two Oncentra plans were preferred because of lower doses to critical organs. One ASA plan was not accepted because of a higher bowel dose.

CONCLUSIONS

Both ASA and Oncentra® planning methods produce acceptable treatment plans for optimized brachytherapy of cervix carcinoma. Continued studies are warranted to further determine the relative strength of each method. This study was supported in part by a research grant from Varian Medical System Inc.

Assessment of the CKD-EPI equation to estimate glomerular filtration rate in adults from a Chinese CKD population

The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation was introduced to estimate glomerular filtration rate (GFR) in chronic kidney disease (CKD) patients based on serum creatinine. The CKD-EPI equation shows better accuracy compared with the current gold standard equation, the Modification of Diet in Renal Disease (MDRD) equation, but it has not been externally validated in Chinese patients. This study compared the CKD-EPI equation with the original MDRD equation and two Chinese MDRD-based equations for estimating GFR in 200 Chinese CKD patients. The (99m)Tc-diethylenetriamine penta-acetate ((99m)Tc-DTPA) method was used to determine actual GFR. The CKD-EPI equation produced GFR estimates that were more consistent with the (99m)Tc-DTPA GFR than did the MDRD equations. The precision and accuracy of the CKD-EPI equation were significantly higher than those of the MDRD equations. In conclusion, the CKD-EPI equation was superior to the existing MDRD equations in terms of estimating GFR and we recommend its clinical use in Chinese CKD patients.

Mesoporous block copolymer nanoparticles with tailored structures by hydrogen-bonding-assisted self-assembly

A simple, yet robust route to prepare polymer nanoparticles with tunable internal structures through supramolecular assembly within emulsion droplets is presented. Nanoparticles with various internal morphologies, including dispersed spheres, dispersed spirals, stacked toroids, and concentric lamellae, are obtained due to the 3D confinement and variation of hydrogen-bonding agent. This method also allows us to form mesoporous particles through further disassembly of the supramoleclar assemblies by rupturing the hydrogen bonding.

Outcomes of maintenance therapy with tacrolimus versus azathioprine for active lupus nephritis: a multicenter randomized clinical trial

AIM

The optimal maintenance therapy for active diffuse lupus nephritis remains to be established. In this study, we explored the efficacy and safety of tacrolimus for maintaining remission of active lupus nephritis compared to that of azathioprine.

METHODS

Seventy patients with biopsy-proven lupus nephritis who achieved remission were enrolled in nine nephrology centers in China from 2006 to 2008. Patients were randomized either to tacrolimus plus prednisone (n = 34) or azathioprine plus prednisone (n = 36) for six months. Tacrolimus was titrated to achieve a trough blood concentration of 4-6 ng/mL, and the dosage of azathioprine was 2 mg/kg/d. Prednisone was administered at a dose of 10 mg/d to both groups. The primary outcome was incidence of relapse. Response, clinical parameters and adverse effects were secondary endpoints.

RESULTS

After six months of therapy, two of the azathioprine-treated patients developed renal relapse compared to none of the tacrolimus-treated patients (p = 0.49; odds ratio, 1.06; 95% CI (0.98, 1.15)). Leucopenia (defined as < 2000 cells per cubic millimeter) was significantly more frequent in the azathioprine group than the tacrolimus group (47% vs. 9%, p < .001).

CONCLUSION

In conjunction with prednisone, maintenance therapy with tacrolimus and azathioprine has a similar low rate of renal relapse, and the tacrolimus regimen has a more favorable safety profile, with less leucopenia. However, since our study lacked sufficient power, longer follow-up is needed to draw final conclusions.

Efficacy and safety of mitiglinide versus nateglinide in newly diagnose patients with type 2 diabetes mellitus: a randomized double blind trial

This study was performed to examine the efficacy and safety of mitiglinide in type 2 diabetes patients (T2DM). Enrolled patients had received treatment with diet and exercise in the previous 3 months with glycosylated haemoglobin (HbA1c) 7-10%, and were randomized to receive mitiglinide (n = 111, 5-20 mg/meal) or nateglinide (n = 114,60-120 mg/meal) for 16 weeks. Primary and secondary efficacy endpoints were assessed by the changes in HbA1c, fasting blood glucose (FBG) and postprandial glucose (PBG) levels. The baseline HbA1c value was 8.2 and 8.3% in both groups. At the end of study, the reduction of HbA1c values from baseline by mitiglinide was slightly more than that by nateglinide (-1.11% vs. -0.76%), but not statically significant (p = 0.06). Final FBG and PBG were comparable for the two treatments. There were 2.8% subjects treated with nateglinide who had hypoglycaemic episodes, but none in the mitiglinide treatment group. The results indicate that mitiglinide and nateglinide had similar effects on FBG, PBG and HbA1c in T2DM patients after the 16-week treatments.

Graphitic tribological layers in metal-on-metal hip replacements

Arthritis is a leading cause of disability, and when nonoperative methods have failed, a prosthetic implant is a cost-effective and clinically successful treatment. Metal-on-metal replacements are an attractive implant technology, a lower-wear alternative to metal-on-polyethylene devices. Relatively little is known about how sliding occurs in these implants, except that proteins play a critical role and that there is a tribological layer on the metal surface. We report evidence for graphitic material in the tribological layer in metal-on-metal hip replacements retrieved from patients. As graphite is a solid lubricant, its presence helps to explain why these components exhibit low wear and suggests methods of improving their performance; simultaneously, this raises the issue of the physiological effects of graphitic wear debris.

Fabrication of silver tips for scanning tunneling microscope induced luminescence

We describe a reliable fabrication procedure of silver tips for scanning tunneling microscope (STM) induced luminescence experiments. The tip was first etched electrochemically to yield a sharp cone shape using selected electrolyte solutions and then sputter cleaned in ultrahigh vacuum to remove surface oxidation. The tip status, in particular the tip induced plasmon mode and its emission intensity, can be further tuned through field emission and voltage pulse. The quality of silver tips thus fabricated not only offers atomically resolved STM imaging, but more importantly, also allows us to perform challenging "color" photon mapping with emission spectra taken at each pixel simultaneously during the STM scan under relatively small tunnel currents and relatively short exposure time.